Liquid crystal display (LCD) televisions and monitors utilize polarizer plates containing polarizer protective films. Polarizer films for LCD televisions and monitors typically contain one layer of doped polyvinyl alcohol (PVA). The doped PVA layer is typically protected by two layers of tri-acetyl cellulose (TAC). Key performance attributes of the polarizer protective film include high total light transmission, low haze, thermal stability and low birefringence. TAC films are traditionally produced by solvent casting methods that are expensive, suffer from low production rates and involve the use of hazardous solvents. Recently, polycyclic olefin films produced by extrusion processes have been used to replace TAC film in polarizer protective film applications. Similarly, polymethylmethacrylate films due to their high light transmission levels and stability have also been evaluated. Unfortunately, the brittle nature of these acrylic films and inability to achieve low birefringence has limited their utilization in polarizer plate and similar applications.
The present invention provides an acrylic film with built-in core/multilayer morphology having similar or better optical performance (high total light transmission, low haze, and low birefringence) as compared to the TAC film product. Such inventive films utilize an inventive polymer composition which provides processing advantages, e.g., melt extrusion in lieu of solvent casting.